2.
    发明专利
    未知

    公开(公告)号:DE2747076A1

    公开(公告)日:1979-04-26

    申请号:DE2747076

    申请日:1977-10-20

    Abstract: An opto-electronic apparatus for reading out preferably coded information contained on a data carrier with high reliability and free of disturbances even when the insertion speed of the information carrier into an associated opening of the reading apparatus depends only on the arbitrary actuation by the operating person, including retrograde motions or stoppage of the information carrier. The apparatus is especially adapted to the read-out of information coded in a card as a pattern of alternating transparent and opaque areas which are subjected to infrared radiation whose passage or non-passage is detected by suitable detectors. The process of reading out the information contained in the data carrier is timed or clocked by a clock cycle generated from a clock trackcontained in the data carrier itself. The apparatus includes a program memory which contains stored information regarding the clock cycle to be expected and is thus able to read out the information contained on the data carrier without automatic mechanical transporting devices for passing the data carrier past the reading assemblies. Even if the manual insertion of the card of the data carrier includes generally unintended reverse motions, the circuit remembers the last clock cycle and continues to read the data at that point during subsequent forward motion, provided the reverse motion has not been excessive. The apparatus also provides the readout and status determination during standby operation with low power sensing pulses and a switchover to data read-out in the presence of the data carrier with high powered pulses of a current density which exceeds that normally acceptable to the light sources under continuous operation. In a preferred embodiment, the coded information on the data carrier is so distributed that, during the read-out of these data, a local clock sequence is generated automatically from the data itself without the requirement for a separate timing track.

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